Must we insist on criticizing questions by new users without even attempting to point them in the right direction where they might find what they need?
I'm speaking primarily of the first comment, which is what led me to write this rant.
As it currently stands, you won't be able to see this question and associated comments unless you have a rep of 20K+ because the OP got frustrated and deleted the whole mess.
Comment #2 was excellent and headed in the right direction. Asking for example images is always good.
But then, after the OP identified the real problem (lighting technique), why couldn't we have pointed the OP in the right direction to find the real answer they needed?
Once the OP mentioned the issues with previous attempts, it would have been easy to provide a link to one of the many product photography questions we have that address those issues. Questions such as Why can't I get a decent white background with product photography? and Why can't I get a pure white background, even using multiple light sources?
Here's a copy/paste version of the question and comments:
What's the best lens for clothes and models?
I have a Nikon D5300, with a kit lens 18-55. I'm using it indoor for taking pictures for clothes (Suits) in my work... I was wondering what could I use to get a better pictures ? A friend of mien recommanded a 17-55 2.8, but I'm not sure about this choice.
Comment 1: Hire a photographer who knows what they are doing. – fkraiem
Comment 2: You have not said what's wrong with your current photos. What is the problem you are trying to find a solution to? – osullic
Comment 3: @fkraiem unfortunately, it's not up to me to do so, I'm not the boss :)
Comment 4: @osullic the photos are dark, and even with the use of softbox, I tried to use withe correction, but I's not enough, the background is gray and the I can't find my way to have a better quality.
Comment 5: Example pictures are worth a thousand words. However, in general, it's usually safe to assume that the tools aren't the problem, it's the proper use of the tools you have that will give you the best results. That is, a new lens is probably not what you should be after. – scottbb
Comment 6: @scottbb you are right, I need to improve my skills while working whit the camera. I love taking pictures, and I enjoy it! specially the night photography, but what's the point of having two similar lens +/- 17-55 and 18-55 with two different apertures ?
Comment 7: I'm sorry, I misread your question based on the title. As written, the title seems to ask for the best lens for fashion/portrait (and I took it to mean, amongst all lenses). However, reading as you intended, "which is the better of these two lenses...", it's a more focused question entirely. – scottbb